In the 18th and 19th century, racialist written works proposed geographically based "scientific" differences among "the races." Many of these racial models assigned colors to the groups described, and some included a "brown race" as in the following:

In 1775, "John Hunter of Edinburg included under the label light brown, Southern Europeans, Sicilians, Abyssinians, the Spanish, Persians, Turks and Laplanders, and under the label brown, Tartars, Africans on the Mediterranean and the Chinese."[3]

In 1915, Donald Mackenzie conceived a "Mediterranean or Brown race, the eastern branch of which reaches to India and the western to the British Isles and Ireland... [and includes] predynastic Egyptians... [and some populations of] Neolithic man".[5]

Due to what he considered the relatively close physical relationship between many populations "from the Red Sea as far as India, including Semites as well as Hamites", Grafton Elliot Smith conceived the Brown Race as a natural extension of Giuseppe Sergi's earlier Mediterranean race concept. In this popular conception, the Brown Race consisted of a joint "Mediterranean-Hamite-Semite" grouping of ancestrally related peoples, into which Elliot Smith included the Proto-Egyptians.[6]

These and other racialist theories have been dismissed scientifically. As a 2012 human biology textbook observes, "These claims of race-based taxonomy, including Coon's claims for homo-sapienation, have been discredited by paleontological and genomic research showing the antiquity of modern human origins, as well as the essential genomic African nature of all living human beings."[7]

In the 19th century, the notion of a single "brown people" was sometimes superseded by multiple "brown peoples." Cust mentions Grammar in 1852 denying that there was one single "brown race", but in fact several races speaking distinct languages.[8] The 1858 Cyclopaedia of India and of eastern and southern Asia[9] notes that Keane was dividing the "brown people" into quaternion: a western branch that he termed the Malay, a north-western group that he termed the Micronesian, and the peoples of the eastern archipelagos that he termed the Maori and the Polynesian.

The appellation "brown people" has been applied in the 20th and 21st centuries to several groups. Edward Telles, a sociologist of race and ethnicity, and Jack Forbes[10] both argue that this classification is biologically invalid. However, as Telles notes, it is still of sociological significance. Irrespective of the actual biological differences amongst humans, and of the actual complexities of human skin coloration, people nonetheless self-identify as "brown" and identify other groups of people as "brown", using characteristics that include skin color, hair strength, language, and culture, in order to classify them.

Forbes remarks upon a process of "lumping", whereby characteristics other than skin color, such as hair color or curliness, act as "triggers" for color categories "even when it may not be appropriate."[10][11]

In 1950s (and later) South Africa the "brown people" were the Coloreds, referring to those born of black-white sexual unions out of wedlock. The Afrikaans terms, which incorporate many subtleties of heritage, political agenda, and identity, are "bruin" ("brown"), "bruines" ("browns"), and "bruinmense" ("brown people"). Some South Africans prefer the appellation "bruinmense" to "Colored".[12][13]

The South African pencil test was one example of a characteristic other than skin color being used as a determiner. The pencil test, which distinguished either "black" from "Colored" or "Colored" from "white", relied upon curliness and strength of hair (i.e. whether it was capable of retaining a pencil under its own strength) rather than upon any color factor at all. The pencil test could "trump skin color".[14][15]

Steve Biko, in his trial in 1976, rejected the appellation "brown people" when it was put to him incorrectly by Judge Boshoff:[16]

Boshoff: But now why do you refer to you people as blacks? Why not brown people? I mean you people are more brown than black.

Biko: In the same way as I think white people are more pink and yellow and pale than white.

Boshoff: Quite ... but now why do you not use the word brown then?

Biko: No, I think really, historically, we have been defined as black people, and when we reject the term non-white and take upon ourselves the right to call ourselves what we think we are, we have got available in front of us a whole number of alternatives ... and we choose this one precisely because we feel it is most accommodating.

Penelope Oakes[16] characterizes Biko's argument as picking "black" over "brown" because for Biko it is "the most valid, meaningful and appropriate representation, even though in an individualistic decontextualized sense it might appear wrong" (Oakes' emphasis).

This contrasts with Piet Uithalder, fictional protagonist of the satirical column "Straatpraatjes" (whose actual author was never revealed but who is believed to have been Abdullah Abdurahman) that appeared in the Dutch-Afrikaans section of the newspaper APO between May 1909 and February 1922. Uithalder would self-identify as a Colored person, with the column targeted at a Colored readership, introducing himself as "een van de ras" ("a member of the race") and characterizing himself as a "bruine mens".[12]

In popular use, Brazilians also use a category of moreno m. [moˈɾenu], morena f. [moˈɾenɐ], lit. 'swarthy', from mouro, Portuguese for 'Moor', which were perceived as people with darker phenotypes than Indigenous Europeans, so a moreno or morena is a person with a "Moorish" phenotype), which is extremely ambiguous, as it can mean "dark-haired people", but is also used as a euphemism for pardo, and even "Black". In a 1995 survey, 32% of the population self-identified as moreno, with a further 6% self-identifying as moreno claro ("light moreno"). 7% self-identified as "pardo".[11]

A comprehensive study presented by the Brazilian Journal of Medical and Biological Research found that on average, 'white' Brazilians have >70% European genomic ancestry, whereas 'black' Brazilians have 37.1% European genomic ancestry. It concluded that "The high ancestral variability observed in Whites and Blacks suggests that each Brazilian has a singular and quite individual proportion of European, African and Amerindian ancestry in his/her mosaic genomes. Thus, the only possible basis to deal with genetic variation in Brazilians is not by considering them as members of color groups, but on a person-by-person basis, as 190 million human beings,with singular genome and life histories".[17]

^David Houze (2006). Twilight People: From Mississippi to South Africa and Back. University of California Press. p. 134. ISBN0-520-24398-6.

^Birgit Brander Rasmussen (2001). The Making and Unmaking of Whiteness. Duke University Press. p. 133. ISBN0-8223-2740-6.

^ abPenelope Oakes (1996). "The Categorization Process: Cognition and the Group in the Social Psychology of Stereotyping". In W. P. (William Peter) Robinson and Henri Tajfel. Social Groups and Identities: developing the legacy of Henri Tajfe. Routledge. ISBN0-7506-3083-3.